Radiation therapy plays an important role in the management of patients with laryngeal cancer. When successful, it allows for preservation of an intact larynx. Although this type of treatment has been utilized for many years, there is very little information detailing the effects of irradiation upon vocal fold function and voice production. the purpose of this project is to document and quantify the acoustic characteristics of the voice patients with carcinoma of the larynx as they undergo irradiation. Measurements of (1) fundamental frequency, (2) phonational range, (3) pitch perturbation, (4) vocal intensity, and (5) acoustic spectra will be obtained prior to, during and after treatment. The fundamental frequency of sustained vowels and connected speech will be obtained via computer analysis. This pitch perturbation during sustained utterances will also be analyzed with computer techniques. All utterances will be studied using spectographic and 1/3 octave analysis techniques. The results of this investigation will serve to document the acoustic changes in the voice as radiological treatment progresses, and, hopefully, provide additional prognostic indicators about the success (or failure) of this treatment approach. The data may also provide an indication of tumor recurrence.